This invention relates to improvements in pillows such that an improved pillow allows the neck of a person who is lying on a bed to be in a neutral and comfortable position. Various embodiments of the improved pillow allow a user to easily adjust its heights.
For a sleeping pillow to be comfortable, it has to satisfy two very different and frequently conflicting requirements:                a. throughout the entire sleeping time, the pillow has to support a neck and a head of a user so as to assure normal, generally straight alignment of a spine, and        b. it has to distribute the pressure under the user's head so as to make it comfortable for the skin on the head and face of the user to rest on the pillow. This may be called Tactile Comfort        
Conventional pillows are generally made in a rectangular shape in one of only a few sizes and are generally filled by a plush down, or polyfill material. However, when a person's head is on the pillow the soft compliant materials compress dramatically and consequently many people try to compensate by using multiple pillows on top of one another. Manufacturers are reluctant to provide a broad range of pillow sizes due to increased production and inventory costs. These pillows frequently address the second requirement of distributing contact pressure by providing soft external surface for the head of the user to rest on but fail to satisfy the first requirement of providing proper height to keep the spine straight.
There are other fill material pillows that use buckwheat or memory foam that provide more support but at the price of reduced Tactile Comfort as they fail to broadly distribute contact pressures leading to reduce comfort.
Generally speaking, a conventional pillow has uniform thickness. When such pillow is too thin (too low) comparing to a distance corresponding to about half of the width of a user's shoulders, the neck of the user lying sideways bends downwards—see FIG. 3. In order to keep a side-lying user's neck straight, a thicker or stiffer pillow must be used to provide higher support when a head is on the pillow. But, when the pillow is too thick such as using two pillows (too high), the neck of the user bends upwards—see FIG. 2. The bent neck may pinch various nerves in the neck, in particular those nerves that come out from the Foramen inter-vertebrates. The pinches may hamper the relaxation or the rest of the nerves and may eventually cause pain in the upper body of a user. Nerve pinch can of course happen when there is not enough support as well. Therefore, a pillow that allows a user to keep a straight neck during sleep is needed.
Frequently, a user has to resort to using not one but a stack of two pillows or to fold the pillow or place their arm under the pillow to assure a proper height. In addition, the fill material of a pillow has a disadvantage of being compressed throughout the sleeping time causing a conventional pillow to gradually reduce its height overnight. Improper height of the pillow therefore causes discomfort and lack of a good night sleep.
In addition, common pillows do not allow for height adjustment tailored to a specific individual's size, mattress firmness and preference, which could change depending on the sleeping position. Known camping pillows are at least partially filled with foam pieces. These pillows feature a turn-on and turn-off valve to control air volume inside the pillow. A user can turn the valve on to open access to the inner inflatable bladder, then the user can inflate or deflate the pillow to a desired state and then the user needs to turn the valve off. Not only this is a long procedure, but it is difficult to adjust the pillow for comfortable sleep while the head of the user is on the pillow. Another disadvantage of these pillows is that the pillow often does not inflate to the maximum height unless the person blows into the valve since the size of the opening is limited making the inflation too restricted. These pillows may also not be optimal when it comes to the choice of foam and fill density.
There is a need therefore for an improved pillow which satisfies all of the above requirements.